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3 years ago

Which of the following is a chemical change?

Chemistry

1 answer:

monitta3 years ago

5 0

Answer: C: A burning candle

Explanation:

C is a Combustion reaction and this is a chemical change.

The rest are physical changed because they are only changing state.

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Put the following metric units in order from largest to smallest pL, mL, dL, kL

earnstyle [38]

Answer:

kL, dL, mL, pL

Explanation:

pL stands for picoliters. This is equal to 1 × 10⁻¹² (0.000000000001) liters.

mL stands for milliliters. This is equal to 1 × 10⁻³ (0.001) liters.

dL stands for deciliters. This is equal to 1 × 10⁻¹ (0.1) liters.

kL stands for kiloliters. This is equal to 1 × 10³ (1000) liters.

8 0

3 years ago

Methyl salicylate is a common active ingredient in liniments such as ben-gay. It is also known as oil of wintergreen. It is made

arlik [135]

Answer: The empirical formula is $C_3H_3O$ .

Explanation:

The chemical equation for the combustion of hydrocarbon having carbon, hydrogen and oxygen follows:

$C_xH_yO_z+O_2\rightarrow CO_2+H_2O$

where, 'x', 'y' and 'z' are the subscripts of Carbon, hydrogen and oxygen respectively.

We are given:

Mass of $CO_2$ = 12.24 g

Mass of $H_2O$ = 2.505 g

Molar mass of carbon dioxide = 44 g/mol

Molar mass of water = 18 g/mol

For calculating the mass of carbon:

In 44g of carbon dioxide, 12 g of carbon is contained.

So, in 12.24 g of carbon dioxide, = $\frac{12}{44}\times 12.24=3.338g$ of carbon will be contained.

For calculating the mass of hydrogen:

In 18g of water, 2 g of hydrogen is contained.

So, in 2.505 g of water, = $\frac{2}{18}\times 2.505=0.278g$ of hydrogen will be contained.

Mass of oxygen in the compound = (5.287) - (3.338+0.278) = 1.671 g

Step 1 : convert given masses into moles.

Moles of C = $\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{3.338g}{12g/mole}=0.278moles$

Moles of H= $\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{0.278g}{1g/mole}=0.278moles$

Moles of O= $\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{1.671g}{16g/mole}=0.104moles$

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For C = $\frac{0.278}{0.104}=3$

For H = $\frac{0.278}{0.104}=3$

For O = $\frac{0.104}{0.104}=1$

The ratio of C : H : O = 3: 3: 1

Hence the empirical formula is $C_3H_3O$ .

5 0

3 years ago

What is a wet celled battery composed of? Give an example of a wet celled battery.

svet-max [94.6K]

Answer:

A wet-cell battery is the original type of rechargeable battery.

An example of a wet cell battery is a lead-acid battery.

Explanation:

3 0

2 years ago

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(b) difference between metalloids and alloys

blsea [12.9K]

Answer:

Metalloid -

A metalloid is a chemical element with properties intermediate between those of typical metals and nonmetals

Alloy -

An alloy is a mixture of metals or a mixture of a metal and another element. Alloys are defined by a metallic bonding character.

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2 years ago

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How does potassium ions behave when current is passed through the electoryte

Mariana [72]

An electrolyte is a substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water.

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2 years ago